Nothing in space stays still. In fact, most stars are like long-distance marathon runners, as they are constantly moving in space throughout their lifetimes. However, astronomers have recently spotted a star (shown in this new space photo as a green smudge in the box) that is better at sprint running.

To work out the speed of this star, astronomers had to figure out how far it has travelled since it started its race and how long this took. Astronomers think the star began its race at the center of the purple cloud of gas and dust in the photo. That's because this is a special type of star that rotates very quickly, which is called a pulsar. And the pulsar was ejected during the explosion that created the cloud of gas and dust.

Based on their estimates, the astronomers think the pulsar is moving at an incredible speed of between 5 million and 7 million miles per hour! This could make it the fastest moving pulsar ever known! But there is a competitor for the title, as another pulsar has previously been estimated to be moving between 3 and 6 million miles per hour.

It's a pity astronomers can't enter these two stars into a 'Space Olympics' to determine which one is the fastest sprinter. Instead, they need to work it out the hard way and fine-tune their results.
[Runtime: 01:48](NASA/CXC/April Jubett)

Astronomers have found a remarkable object in our Milky Way galaxy. This object is a pulsar, the spinning dense core that remains after a massive star has exploded and collapsed. When this pulsar was created, something interesting happened because this pulsar is racing away from the supernova remnant where it was born at a speed between 2.5 million and 5 million miles per hour. This supersonic pace makes this pulsar - called IGR J1104-6103 -- one of the fastest moving pulsars ever observed. And what's more is that this runaway pulsar is leaving behind an extraordinary tail behind it as it goes. This tail is about 37 light years in length, making it the longest X-ray jet ever seen from an object in the Milky Way galaxy. New data from NASA's Chandra X-ray Observatory have been combined with radio data from the Australia Telescope Compact Array to provide astronomers with a more complete picture of what's happening in this system. For example, these data show that the tail has a distinct corkscrew shape. This suggests that the pulsar is wobbling like a top as it spins. IGR J1104-6103 is located about 60 light years away from the center of the supernova remnant SNR MSH 11-61A, which is where astronomers think the pulsar was originally created. By examining the details of the pulsar, its jet, and the supernova remnant, astronomers are piecing together the story of this exceptional object in our Galaxy.
[Runtime: 01:54](NASA/CXC/A. Hobart)

About once or twice every 100 years, a gigantic nuclear bomb detonates in our Galaxy. In just a few short weeks, it blasts out as much energy as our Sun will in its entire lifetime! This powerful explosion is called a 'supernova', and it is the result of a star dramatically ending its life.

The most recent supernova in our galaxy, the Milky Way, happened just over 100 years ago. But, unfortunately for our great-great-great grandparents, the explosion was hidden behind thick clouds of gas and cosmic dust, far away from the Earth. So they couldn't witness this very rare sight. Because of this cosmic dust, it wasn't until 2008 that a group of astronomers finally stumbled upon the remains of the obliterated star, which you can see in this photograph.

Normally, when a supernova like this happens, the star's material is blown out evenly in all directions. This leaves behind a cloud that is more or less neat and symmetrical, but the object in this picture doesn't follow a neat pattern. Most of the star's material was blasted towards the top of the picture, and it's still travelling in that direction extremely fast. From these clues, astronomers have deduced that this must have been an unusually energetic and messy supernova explosion!

As far as we know, the last supernova in the Milky Way was over 100 years ago. If they happen on average every 100 years or so, another one should be due really soon. Keep your eyes on the skies and you might be the one to spot it first!
[Runtime: 02:05](NASA/CXC/April Jubett)

One of the most famous objects in the sky – the Cassiopeia A supernova remnant – is now on display like never before, thanks to NASA's Chandra X-ray Observatory and a new project from the Smithsonian Institution. A new 3D viewer developed by the Smithsonian allows users to interact with one-of-a-kind objects like the Wright Brothers airplane and a 1,600-year-old stone Buddha. The only astronomical object in this special collection is Cassiopeia A, or Cas A for short.

Back in 2009, scientists combined data from Chandra, NASA's Spitzer Space Telescope, and ground-based facilities to construct a unique 3D model of Cas A, which is a 300-year old debris field that was created when as a massive star exploded. This new Smithsonian viewer will allow scientists and the public to tour this 3D model Cas A in exciting new ways by being able to fly around the remnant themselves. Users can also get more information about various parts of the supernova remnant by clicking on hotspots and following links to more in-depth articles. So we invite you to take a 3D ride unlike any you'll find at the movie theater and explore Cas A in in a brand new one way.
[Runtime: 02:09](NASA/CXC/April Jubett)

Like the famous detective Sherlock Holmes, astronomers have to be good at solving puzzles by piecing together clues and evidence. When scientists using the Chandra X-ray Observatory noticed the strange, distorted shape of this supernova remnant, they knew something unusual had taken place. After scouring through their data and arguing against other possibilities, astronomers realised they may have uncovered a dark secret lurking within this picture - a young black hole!

The supernova explosions that tear apart massive stars normally blast away material evenly in all directions and leave behind a symmetrical bubble (the same on both sides). However, in this supernova, material from the north and south poles of the star (yes, stars have poles, too!) was blasted out much faster than anywhere else. The resulting barrel-shaped remnant gave astronomers their first clue that this star's life ended in an unusual way.

Most of the time when a star goes supernova, the remaining core is squashed down into a tiny ball called a neutron star. Neutron stars normally give off X-ray radiation, which astronomers can photograph using special telescopes. But a careful search of the data showed no X-ray radiation or other evidence for a neutron star. This means an even more exotic object was probably formed during the explosion - a black hole! If this turns out to be correct, it'll be the youngest known black hole in our entire Galaxy, at just 27,000 years old!
[Runtime: 02:02](NASA/CXC/April Jubett)

In 1604, a new star appeared in the night sky. It shone brighter than all the other stars, and for three weeks, it was even visible during the day&33; This mysterious beacon marked the explosive death of a nearby star. These explosions are called supernovas, and they give off so much light that for a few weeks, they can outshine a galaxy of billions of stars! Then, slowly they fade away, leaving behind beautiful glowing clouds of gas, like the one in this picture.But let's travel back to a few million years earlier, because the story of this star gets even more interesting. The star that exploded in 1604 began its life as an average star, similar to our Sun. When an average-sized star dies, the result is much less dramatic than a powerful supernova. Instead of exploding, it expands to become a red giant and then collapses. The material from the centre of the star ends up squashed tightly down into a tiny, heavy ball called a white dwarf star. This is how this star died for the first time, long before 1604. But how did it end up dying a second time? Well, astronomers have recently discovered the answer to that question. The white dwarf had a companion, an enormous red giant star. Even though the red giant was much larger, the white dwarf's gravity was much stronger. It began to rip gas off its companion, pulling the material onto itself. Eventually the star's own greed led to its demise. It stole so much material that it became unstable, leading to the spectacular explosion that our ancestors saw&33;
[Runtime: 02:29](NASA/CXC/A. Hobart)

Astronomers estimate that a star explodes as a supernova in our Galaxy, on average, about twice per century. In 2008, a team of scientists announced they discovered the remains of a supernova that is the most recent, in Earth's time frame, known to have occurred in the Milky Way. The explosion would have been visible from Earth a little more than a hundred years ago, if it hadn't been heavily obscured by dust and gas. Today, that object is known as the supernova G1.9+0.3 or G1.9 for short. A new long observation -- equivalent to more than 11 days of Chandra time -- of explosion's debris field is providing new details about G1.9. The source of G1.9 was most likely a white dwarf star that underwent a thermonuclear detonation and was destroyed - either after merging with another white dwarf or by pulling too much material from an orbiting companion star. The explosion ejected the remains of the destroyed star, creating the supernova remnant seen today by Chandra and other telescopes. The new Chandra data show that the explosion that created G1.9 was different than other supernovas like it. For starters, the remnant's debris is unevenly distributed, while most other supernova remnant are highly symmetrical. Also, researchers found that some of the debris - particularly iron that would have been in the star's core before the explosion -- is moving at extremely high speeds. By combining these clues from the Chandra data with theoretical models, scientists think that the explosion that created G1.9 must have been highly irregular and abnormally energetic.
[Runtime: 01:56](NASA/CXC/J. DePasquale)

This year, astronomers around the world have been celebrating the 50th anniversary of X-ray astronomy. Few objects better illustrate the progress of the field in the past half-century than the supernova remnant known as SN 1006.

When the object we now call SN 1006 first appeared on May 1, 1006 A.D., it was far brighter than Venus and visible during the daytime for weeks. Astronomers in China, Japan, Europe, and the Arab world all documented this spectacular sight. With the advent of the Space Age in the 1960s, scientists were able to launch instruments and detectors above Earth's atmosphere to observe the Universe in wavelengths that are blocked from the ground, including X-rays. SN 1006 was one of the faintest X-ray sources detected by the first generation of X-ray satellites. A new image of SN 1006 from NASA's Chandra X-ray Observatory reveals this supernova remnant in exquisite detail. By overlapping ten different pointings of Chandra's field-of-view, astronomers have stitched together a cosmic tapestry of the debris field that was created when a white dwarf star exploded, sending its material hurtling into space. The kind of supernova is called Type Ia, and astronomers use observations of these explosions in distant galaxies as mileposts to mark the expansion of the Universe. The new Chandra data provide new details about these important objects. In many ways, SN 1006 represents just how far we have come in exploring our Universe in the past fifty years and the progress we continue to make.
[Runtime: 01:46](NASA/CXC/A. Hobart)

Over 400 years ago, Johannes Kepler and many others witnessed the appearance of a new "star" in the sky. Today, this object is known as the Kepler supernova remnant. For some time, astronomers have thought that the Kepler remnant comes from a so-called Type Ia supernova. These supernovas are the result of a thermonuclear explosion of a white dwarf. However, there is an ongoing controversy about Type Ia supernovas. Are they caused by a white dwarf pulling so much material from a companion star that it becomes unstable and explodes? Or do they result from the merger of two white dwarfs? New Chandra images reveal a disk-shaped structure near the center of the remnant. Researchers interpret this X-ray emission to be caused by the collision between supernova debris and disk-shaped material that a giant star expelled before the explosion. This and other pieces of evidence suggest that at least the Type Ia explosion that created Kepler was not the result of a merger between white dwarfs. Since these supernovas are used to measure the expansion of the Universe itself, astronomers are eager to understand them inside and out.
[Runtime: 01:26](NASA/CXC/A. Hobart)

This video shows a simulation of the Kepler supernova as it interacts with material expelled by the giant star companion to the white dwarf before the latter exploded. It was assumed that the bulk of this material was expelled in a disk-like structure, with a gas density that is ten times higher at the equator, running from left to right, than at the poles. The colors represent the density of the gas, using a rainbow distribution, with red showing the highest densities, followed by orange, yellow and green, then blue showing the lowest densities. Note the dense structure on the left and right of the explosion. This simulation was performed in two dimensions, so this is a cross-section of the explosion. The simulation has to be projected into three dimensions to compare with observations. The good agreement with Chandra and Spitzer data supports the author's interpretation of the disk-like structure they observed.
[Runtime: 00:13](NASA/CXC/NCSU/J.Blondin et al.)